The present invention relates generally to fluorescent lamps used in tanning beds, and particularly to an electrode shield for use therewith.
Fluorescent lamps generally have a limited service life. The service life is proportional to the life of the electrode and emission material. The emission material may be expended due to ion bombardment, vaporization of emission material, and chemical reactions between the emission material and gaseous impurities in the lamp. The starting process additionally produces higher voltages, which reduce the life of the lamp. This is particularly troublesome in tanning lamps, which use relatively high current and are cycled on and off repeatedly. Tanning lamps generally have currents ranging between 800 milliamperes and 2000 milliamperes. This current is higher than the typical fluorescent lamp current, which may range between 400 milliamperes and 800 milliamperes. Heat generated from the higher currents in a tanning lamp also result in shorter lamp life. Therefore, there is a need for an improved fluorescent tanning lamp structure that improves performance and increases the useful life of a fluorescent tanning lamp.
The present invention is directed to a florescent tanning lamp with an improved service life. A tanning lamp has an electrode at either end of a glass tube. A cup having an open end contains or surrounds each of the electrodes and acts as an electrode shield. In one embodiment, the cup is mounted on an insulated stem of the fluorescent tanning lamp and is electrically insulated from the electrode. In another embodiment, the cup is supported by a cup support attached to an electrode support or a lead wire attached to the electrode and is electrically and thermally coupled thereto and aids in shielding and dissipating heat from the cup.
Accordingly, it is an object of the present invention to provide an improved fluorescent tanning lamp that has an increased service life.
It is another object of the present invention to provide a fluorescent tanning lamp that can accommodate repeated on and off cycles while minimizing any reduction in service life.
It is an advantage of the present invention that reduced sputtering impurities are entered into the arc stream resulting in cleaner phosphor surfaces and providing a longer effective UV output.
It is a further advantage of the present invention that a more uniform electrode temperature is obtained resulting in less severe evaporation of emission material, thereby reducing contamination of the phosphor.
It is a further advantage of the present invention that a cooler cold spot temperature is obtained behind the electrode providing a more stable mercury vapor pressure.
It is a feature of the present invention that a cup surrounding the electrode is electronically coupled to a lead wire of the fluorescent tanning lamp.
These and other objects, advantages, and features will become readily apparent in view of the following more detailed description.